Drill



I Aug. 30, 1927. q 1,640,810

- 5. T. SKEEN DRILL Filed Sept. 25, 1923 AWE/Wok 5. ZJKEf/Y ArfaermrsPatented Aug. 39,1927,

NITE STATES v g 1,64a8le PATENTTOFFICE.

ear/mm. r. or cnnrnama, ILLINOIS, Assrenon or onnnanr T0 onAaLn-s srnan,or OENTRALIA, rumors.

DRILL.

This invention relates to a drill particularly adapted for use indrilling into coal deposits, one of the objects'being to provide a verysimple and inexpensive niiners dr1ll having a blade or bit which 'may beeaslly detached from the blade-holder. The blade is preferably formed ofa single piece of metal and is rigidly secured to an end portion of along spiral stem, and since the blade is small and inexpensive article,it may be economically made of a high grade material well adapted towithstand the serviceto which it is subjected.

An important advantage in my drill is the drill stems, may be removedand replaced by other blades whenever necessary, thereby eliminatingthenecessity of taking the drill from the mine to sharpen the blades, asis ordinarily done. Due to the fact that the wear is on the detachableblades and not on the drill stems, it isapparent that a single drillstem may be used for a long period of time. a

With the foregoing and other objects in View, the invention comprisesthe novel con- 7 struction, combination and arrangement of partshereinafter more specificallydescribed and illustrated in theaccompanying drawings wherein is shown the preferred embodiment of theinvention. However, it is to be understood that the inventioncomprehends changes, variations and modifications which come within thescope of the claims hereunto in the form of a spiral conveyor having itsend B flattened, as illustrated in Fig. III,

i said stem being provided with a slot 1 which extends longitudinally ofsaid flattened end portion. The slot 1 is open at its outer end and acircular opening 2 of greater diameter than the width of said slot islocated at the inner end of said slot, said slot being in communicationwith said circular opening.

The'blade 3 is preferably formed of a 'hat the drill blades, beingdetachable from.

Application filed September 25, 1923. Serial No. 664,666.

singlepiece of material provided with cuttingedges 4, and includes. anintegral counterboring blade 5. The blade 3 is provided with abifurcated upper portion com prising a portion 6 and a portion 7, saidlade being bent in .a manner to provide a wall 8 which extendslongitudinally of said blade. The operation of bending-the blade so that'it assumes the shape shown most clearly in big. II separates'theportions 6 and 7, one from the other, in a direction which is at rightangles to the side -faces of said portions 6 and 7, a distance equal tothe thickness of theflattened portion B of iv the drill stem A. Theblade 3 is provided with a circular opening, 9 which is 'approxi-'mately the same diameter as the opening 2 in the portion B of the drillstem, said opening 9 being located at the inner end of the slit 10 whichseparates the portions 6 and 7' from each other.

To assemble the drill stem A and the blade 3 of my improved drill theblade is brou ht to a, position where the space between the portions 6and 7 of said blade is in alinement with the flattened port-ion of thedrill stem.

The blade at this time is so positioned that the slot 1 in saidflattened portion B of the drill stem will be in alinement with thewall/ 8 of the blade.

The blade 3 is then moved inwardly toward the inner end of the slot 1until the end B of the flattened portion B of the drill stem contactswith the inner face i of the wall 3 of the blade 3, which wall is solocated that t-he circular opening 9 of the blade registers with thecircular opening 2 of the drill stem. Y I

hen the drill stern and the blade have been assembled as described, bolt11 is passed through the registering openings 2 and 9 and a nut 12 isscrewedon an end of time 6 or 7 and the inclined portion contacting withan adjacent face of the flattened portion 13 of the. drill stem A (Fig.II).

. nil

on said stem.

From the foregoing it is plain that the blade may be very readilyattached to or detached from the stem of my improved drill, and when theblade and the drill stem are assembled as described it is apparent thatsaid blade is very securely attached to said drill stem, for the reasonthat the slot 1 in the drill stem and the slit 10 of the blade are ofinsuiiicient widths to permit the passage of the bolt through.

referring to Fig. 11 it will be seen that when the drill is in use andis being rotated in the direction indicated by the arrow in this view,the flat inner faces of the portions 6 and 7 will be in contact with theopposite side faces of the portion B of the drill stein, thus relievingthe bolt 11 of much of the strain caused by the cutting action, and saidboltmerely acting to hold the blade and the drill stem together.

I claim:

1. A drill comprising a stem, a blade provided with a bifurcated portionadapted to cooperate with an end portion of said stein whereby saidblade may be detachably attached to said stem, the oppositely disposedleg portions of said bifurcated portion of said'blade being out ofalinement with each other and flat side faces of said leg portions beingin contact with the opposite side faces of said end portion of saidstem, and means whereby said blade is securely held in place or )risi as'em nvin c ii- 2 A illcom n t la gal furcated end portion, a bladeprovided with a bifurcated portion adapted to cooperate with thebifurcated portion of said stein whereby said blade may be detachablyattached to said stem, the oppositely disposed leg portions of saidbifurcated portion of said blade being out of alinen'iont with eachother and flat side faces of said leg portions being in contact with theopposite side faces of said end portion ofisaid stem, and means wherebysaid blade is securely held in place on said stem. 7

3.1K drill comprising a stem having an elongated opening adjacent to oneof its ends, a blade provided with an elongated 11 longitudinallythereopening, a portion of said stem being adapted to be inserted intothe elongated opening in said blade and a portion of" said blade beingadapted to be inserted intothe elongated opening in said stein wherebysaid blade may be detachably attached to said stem, the portions of saidblade at the oppo "site sides of the elongated openingtherein being outof alinement with each other and blade having portions separated onefrom the other and adapted to contact with the opposite sides of saidflattened end portion of said drill stem, said drill stem'andsaidbladehaving openings adaptedto register one with the other, and afastening device adapted to be passed through said'register-- said drillstem.-

5. A drill comprising a stem having a flattened end portion providedwith an elon gated slot, a blade provided with awall ing openings tosecure said blade through adaptedto pass into said slot, said blade (illblade adapted to pass into said slot, said having portions separated onefrom theother to provide an elongated openinf said blade, portion ofsaid stem b ing adapted to pass into said elongated opening! in saidblade, and said separated portions ofsaid blade being adapted to contactwith opposite sides of said flattened portion of said stem, said bladeand said stem having circular openings adapted to register with eachother, said circular openingsbeing in com munication with said.elongated slot in the end-portion of said stem and the elongated openingin said blade, and a bolt adapted to v i be passed through saidregistering openings to secure said blade tosaid stem.

In testimony that I claim the foregoing I hereunto aflix my signature.

SAMUEL r. SKEEN.

